The Lactate/Albumin Ratio Predicts Mortality in Critically Ill Patients with Acute Kidney Injury: An Observational Multicenter Study on the eICU Database

Xu Zhu; Jing Xue; Zheng Liu; Wenjie Dai; Hui Xu; Qiaoling Zhou; Shuangping Zhao; Quan Zhou; Wenhang Chen

doi:10.2147/IJGM.S339767

The Lactate/Albumin Ratio Predicts Mortality in Critically Ill Patients with Acute Kidney Injury: An Observational Multicenter Study on the eICU Database

Int J Gen Med. 2021 Dec 30:14:10511-10525. doi: 10.2147/IJGM.S339767. eCollection 2021.

Authors

Xu Zhu¹, Jing Xue², Zheng Liu³, Wenjie Dai⁴, Hui Xu⁵, Qiaoling Zhou⁵, Shuangping Zhao⁶, Quan Zhou⁷, Wenhang Chen⁵

Affiliations

¹ Department of Epidemiology and Health Statistics, College of Integrated Traditional Chinese and Western Medicine, Hunan University of Chinese Medicine, Changsha, Hunan, 410208, People's Republic of China.
² Department of Scientific Research, Xiangya Hospital, Central South University, Changsha, Hunan, 410008, People's Republic of China.
³ Department of Anesthesiology, Shandong Provincial Qianfoshan Hospital, The First Hospital Affiliated with Shandong First Medical University, Ji'nan, Shandong, 250014, People's Republic of China.
⁴ Xiangya School of Public Health, Central South University, Changsha, Hunan, 410008, People's Republic of China.
⁵ Department of Nephrology, Xiangya Hospital, Central South University, Changsha, Hunan, 410008, People's Republic of China.
⁶ Department of Intensive Care Unit, Xiangya Hospital, Central South University, Changsha, Hunan, 410008, People's Republic of China.
⁷ Department of Science and Education, The First People's Hospital of Changde City, Changde, Hunan, 415000, People's Republic of China.

Abstract

Objective: The serum lactate/albumin ratio (LAR) can be used to independently predict mortality due to sepsis. However, whether the LAR predicts the outcomes of critically ill patients with acute kidney injury (AKI) remains unclear. This study was performed to assess the prognostic value of the LAR in critically ill AKI patients.

Methods: This retrospective observational study enrolled AKI patients, and all data were collected through the eICU Collaborative Research Database. Outcomes included in-hospital and intensive care unit (ICU) death. Multivariate Cox regression analysis was used to determine independent risk factors. Forest plots and smoothing curves were generated. A series of subgroup analyses were performed to further validate the robustness of the findings.

Results: A total of 4666 eligible patients were enrolled. We divided the participants into four groups according to the LAR: quartile (Q)1 (LAR < 0.46, n = 1167), Q2 (0.46 ≤ LAR < 0.79, n = 1162), Q3 (0.79 ≤ LAR < 1.49, n = 1170), and Q4 (LAR ≥ 1.49, n = 1167). The LAR, when analyzed as a continuous variable, was associated with hospital and ICU mortality (adjusted hazard ratio [HR] 1.22, 95% confidence interval [CI] 1.18-1.26, P < 0.0001 for both). The risk of in-hospital and ICU mortality increased with increasing LAR Q relative to Q1. The smoothing curves revealed a continuous linear association after adjusting for all covariates. By the Kaplan-Meier analysis, patients in the higher LAR group showed significantly shorter survival time. By the receiver operating characteristic analysis, LAR was efficient in predicting in-hospital mortality (area under the curve [AUC]: 0.717) and ICU mortality (AUC: 0.733). A positive and consistent effect of the LAR was seen in all subgroups analyses after adjusting for all covariates.

Conclusion: A high LAR is an independent risk factor for in-hospital and ICU mortality in critically ill patients with AKI. Further prospective studies are needed to validate these result.

Keywords: acute kidney injury; critical care; lactate/albumin ratio; mortality.

Grants and funding

Funding sources: Supported by Changsha Municipal Natural Science Foundation (No. kq2014276), Scientific Research Project of Hunan Provincial Health Commission (No. 202103050756), Provincial Natural Science Foundation of Hunan (No. 2021JJ40972), National Youth Science Foundation of China (No. 81600536).